Bolt rethreader



h I l I l BOLT RETHREADER LE ROY J. KNETTLE Filed Oct. 3, 1938 July- 25, 1939.

Patented July 25, 1939 UNITED STATES BOLT RETHREADER Le Roy J. Knettle, Gloucester, J.

Application October 3,

4 Claims.

1938, Serial No. 232,935 (01. 10-105) (Granted under the act of March 3, 1883, as

amended April 30,

This invention relates to a device for rethreading used bolts and has for an object to provide a machine which may be used in a quick and easy manner for rethreading used bolts.

A further object of this. invention is to provide a bolt rethreading machine which is operable so that it maybe set up at a position convenient to the work being performed.

A further object of this invention is to provide a bolt rethreading machine having a rotatable disc into which the bolts may be fed into proper position for rethreading and then discharging the rethreaded bolts into a suitable placed receptacle.

A further object of this invention is to provide a bolt rethreading machine of an operable nature wherein the operating machine included thereon may be pneumatically operated, thereby permitting the use of the machine at any place where a source of pneumatic power may be available.

With the foregoing and other objects in view, the invention consists in the construction, combination and arrangement of parts hereinafter described and illustrated in the drawing, in which:

Fig. 1 is a front elevational View of the rethreading machine.

Fig. 2 is a side view of Fig. 1; and,

Fig. 3 is a fragmentary View on line 33 of Fig. 2.

There is shown at ii] the rethreading machine of this invention including a table top I! supported on table support brackets l2. The brackets l2 extend forwardly from a rear wall or bracket l3 suitably supported in any convenient manner. A pair of tracks 14 are provided on which may be reciprocated the threading machine carriage l5 supported between a front plate iii-and a rear plate I? held together by long bolts I8. The machine within the carriage I5 is pneumatically operated, being connected to a source of pneumatic power by the pipe 26 passing through a hollow handle 2 l. Another handle 22 on the opposite side thereof facilitates the operation of the machine. Inserted in the machine is a shank 23 to which is secured a pipe cap 24 carrying pipe socket 25 within the end of which is located a bolt die 25, the bolt die 26 being removably held in position in a suitable manner within the socket by band 21 so that bolt dies of different threads may be substituted according to the size of bolt that is to be rethreaded.

Extending downwardly through a slot 28 in the tab-le surface .is the shaft trip lever 3! provided with a slot73! through which extends a pin 32 i for transversely moving the link 33 connected at one end to a'bellcrank 34 and operatingagainst the springs 35 and 36 tending to restore it to the. 5 position shown in Fig. 2.

As will be apparent, withdrawing the machine carriage I5 over thetracks M toward the edge of the table will cause the bell crank 34 to move about its pivot 39 inaclockwise direction. This action may be supplementedby means of the bell crank lever 3"! provided with a slot 38 cooperatingwith pin 32 and adapted to rotate about its pivot 41? ina counter-clockwise direction when drawn by the link it attached to thefoot 5 treadle lever 42 pivoted. as at 43., Placing the foot on the treadle 44 and pressing downwardly facilitates withdrawal of machine carriage toward the end of the table.

A front bracket v45 supported on the table II and braced by an arm 46 from. the rear bracket l3 is'provided with a center bolt 4? on which is pivoted the bolt discflfi. This bolt disc 48 includes a backing plate 58 adjacent to which is a bolt disc head 5! next towhich is a bolt disc; locking plate 52 and in the front is a bolt disc support plate 53. The disc 48 is held assembled by a plurality of tap bolts 54.

When different sized bolts and bolt heads are to be worked on, the head plate and locking plate A may be changed for other plates having appropriate sized slots in the edges thereof so as to receive and support the bolts. The guard 55 adjustably held in position by the bolt 56 holds the bolts 51 in position in the slots after they are placed'therein at the top of the disc until they have come around the bottom in front of the bolt die 26 carried by the machine carriage 15.

An oil reservoir 58 with a control valve 50 has a discharge pipe 51 from which depends a piece of chamois 62 for lubricating the bolts 51 andfacilitating their rethreading by the bolt die 26. After the bolts 5! have been rethreaded they pass successively beyond the lower edge of the guard 55 and drop into a chute 63 leading through the table II into a suitably placed receptacle 64.

At the end of each rethrea ding operation the machine carriage i5 is withdrawn toward the edge of the table, causing bell crank 34 to rotate in a clockwise direction. This bell crank 34 has 5 a connecting rod 55 connected by a link 6% to one end of a lever B! pivoted at 68 to the bracket 65. The other end of the lever 61 is provided with a pawl finger iiiyieldably held in position by a ,tension spring H. As the bell crank lever 34 55 '20 8| will cause retraction of the'locking pin 14 ing the locking plunger to be withdrawn in cam block 88 shaped as shown and adapted to rotatesin a clockwise direction the pawl finger 18 moves upwardly into the nearest slot '12 of the disc 48 and rotates the disc 48 a distance equal to the distance between the bolt slots 12. When the bell crank34 returns in a counter-clockwise direction to its normal position the finger l0 pivots as at 13 against the tension spring, allowing the lever 8'! to likewise be returned to its normal position. 7

To insure that the disc 48' will be in proper position holding the lowermost bolt 51 exactly centered with the path of the bolt die '25 on machine carriage ,l 5, a locking plunger 14 is yieldably held in suitably positioned recesses in the back of disc 48 by means of a spring 15 operating against a plug 16 in a cylinder Ti. The locking plunger 14 carries a sleeve" against f which the bifurcated end 8i] of a trip bar 8| may press. The'trip bar 8! is pivoted asat8'2 whereby a forward motion of the lower end of the trip bar from the locking aperturesin the disc 48 alloworder to rotate the disc 48.

An arm'83 extends through the lower end of trip bar8l and is pinnedthereto as'at 84 whereby forward motion of the arm 83, toward the front 7 edge of the table pivots the trip. bar 8| to withdraw the lockingfplunger l4 fromengagement "30 with. the disc148. The arm 83 is secured to the rear end of a releasecam bar 85 held on the bottom of the table H by supporting brackets 86.

A' tension spring 81 tends toholdjjrelease' cam bar in the normal full line position shown in Fig.3. The release cam bar 85 carries a release contact with amain cam block 90 carriedby a main cam 9| slidabl on brackets 92 against a spring 93. A trip bracket 94 secured to' the main cam 9i extends through a slot 95 in the table H and is provided with a bracket head 98111 the path of the machine carriage plate I'L- The release cam bar 85 also carries an angular adjusting'arm 91 which contacts with an adjusting bolt 98 threaded through a nut H10 secured to the bottom of the table II. Retraction of the machine carriage l5 away fromthe disc 48 to- V ward the end of the table II forces the plate I! to contact the bracket head86 and pull the main cam 91 in the same direction, the .main cam blockv 90 similarly pulling ,on the release cam block 88, thus pulling the release cam bar 85 to withdraw the locking plunger 14 from the disc 48.

The adjusting arm 91 against the end of bolt 98 causes the release cam bar 85 to simultaneously move transversely to the dot dash line position 85', allowing release cam block 88 to disengage from the main cam block 90, the spring 81 immediatelyrestoring the release cam bar 85 to normal position, thus allowing spring I5 to press the locking plunger 14 into the appropriate looking aperture.

In operationfth'e operator feeds bolts 51' intothe slots 12 at the top of the disc 48 one by one. With the plunger 14 holding the disc 48 against rotation'the machine carriage i5 is moved forwardly in its tracks I4,'the power being turned on by suitable manipulation ofthe handle 2| on the power conduit 28 and the carriage moved forwardly causing the bolt die 28 to engage the lowermost bolt 51' and appropriately thread it. The handle 2| is'then manipulated to reverse the rotation of the die 26, allowing it to disengagefrom the bolt 51 and the carriage is withdrawn toward the end of the table II on tracks [4.

release cam block 88'to pull the release cam and trip bar 8| to withdraw the locking plunger;

14 from contact in the appropriate aperture in disc 48, releasing the disc48 from locking engagement therewith just as pawl finger "i8 contacts the side of slot EZ'to rotate the disc 48.

Slight further movement of the machine carriage along the table II releases the cam blocks and88 from interengagement and the release 7 cam bar 85 is restored to normal position, allowing the spring 15 to force the plunger 14 into the next appropriate locking aperture in disc 48 ,as

the lever 61 completes its pivoting movement.

Machine carriage 15 is then ready to be pressed 7 forwardly and thread thexnext successive bolt 51 now held in appropriate position by the disc 48 being held locked by the locking plunger 14.

The curved shapes of the backs of the cam blocks 88 and 98 permit the main cam block 90 to be drawn past the release cam block 88 by the tension spring 93, release cam spring 87 yield ing slightly to permit this movement and to then restore the release cam 85 to the normal position with the-cam blocks 88 and 98 in interene gagement, as shownin full lines in Fig. 3, ready forthe next operation. The same operation is repeated with eachbolt as itis'rethreaded and then discharged throughthe chute 63 to receptacle 64. Other modifications and changes in the proportions and arrangements of the parts may be made by those skilled in the art without depart ing from the nature of the invention, within the scope of what ishereinafter claimed.

The invention described herein maybe manufactured and/or used by or for the Government tatable bolt-holding disc, means for locking said disc against rotation, a bolt-threading die adapted to engage a bolt held in said bolt-holding disc, means supporting said bolt-threading die 1. A bolt rethreading device comprising a ro-' for reciprocation to bolt-threading and bolt-disengaging position, means operable by the reciprocation of said threading die for unlocking the disc and rotating the disc while the threading die is disengaged from the bolt to be threaded, L

said locking means comprising a spring-pressed plunger and a series of suitably spaced apertures in said disc into any one of which said plunger may selectively penetrate to lock said disc, said nected tosaid main cam bar extending into the path of said reciprocating threading die tooperate said cam bar as said rethreading die is reciprocated away from said disc.

2. A bolt rethreading machine comprising a rotatable bolt-holding disc, means for looking said disc against rotation, a bolt-threading die adapted to engage a bolt held in said bolt-holding disc, means supporting said bolt-threading die for reciprocation to bolt-threading and boltdisengaging position, means operable by the reciprocation of said threading die for unlocking the disc and rotating the disc while the threading die is disengaged from the bolt to be threaded, said locking means comprising a spring-pressed plunger and a series of suitably spaced apertures in said disc into any one of which said plunger may selectively penetrate to lock said disc, said unlocking means including a pivoted lever, one end of which is connected to said locking plunger, a release cam bar connected to the other end of said pivoted lever, a main cam bar adapted to engage said release cam bar, means connected to said main cam bar extending into the path of said reciprocating rethreading die to operate said cam bars as said rethreading die is reciprocated away from said disc, said disc rotating means including a pivoted lever, a pawl at one end of said lever to engage said disc to rotate the same, a link at the other end of said lever, and means connecting said link to said die to operate said link and pivot said lever as said die is reciprocated.

3. A bolt rethreading machine comprising a rotatable bolt-holding disc, means for locking said disc against rotation, a bolt-threading die adapted to engage a bolt held in said bolt-hold. ing disc, means supporting said bolt-threading die for reciprocation to bolt-threading and boltdisengaging position, means operable by the reciprocation of said threading die for unlocking the disc and rotating the disc while the threading die is disengaged from the bolt to be threaded,

said disc rotating means including a pivoted lever, a pawl at one end of said lever to engage said disc to rotate the same, a link at the other end of said lever, means connecting said link to said die to operate said link and pivot said lever as said die is reciprocated, said last mentioned means comprising a bell crank to which said link is connected, a shaft connected to said bell crank, a trip bar connected to said die, and a pin and slot connection between said trip bar and said shaft.

4. A bolt rethreading machine comprising a rotatable bolt-holding disc, means for locking said disc against rotation, a bolt-threading die adapted to engage a bolt held in said bolt-holding disc, means supporting said bolt-threading die for reciprocation to bolt-threading and boltdisengaging position, means operable by the reciprocation of said threading die for unlocking the disc and rotating the disc while the threading die is disengaged from the bolt to be threaded, said disc rotating means including a pivoted lever, a pawl at one end of said lever to engage said disc to rotate the same, a link at the other end of said lever, means connecting said link to said die to operate said link and rotate said lever as said die is reciprocated, said last mentioned,- means comprising a bell crank to which said link is connected, a shaft connected to said bell crank, a trip bar connected to said die, a pin and slot connection between said trip bar and said shaft, a second bell crank, a pin and slot connection between said second bell crank and said trip bar, and a foot treadle connected to said second bell crank to assist in operating said shaft.

LE ROY J. KNEI'ILE. 

